Operating system update management

ABSTRACT

Disclosed aspects relate to operating system update management for a shared pool of configurable computing resources having a plurality of logical partitions (LPARs). An operating system update request may be received. A set of original shared portions and a set of original individualized portions may be classified with respect to a set of original files on a set of original nodes. A set of original overlay links may be created for the set of original files. A set of operating system network traffic may be routed using the set of original overlay links. A set of successor files may be established on a set of surrogate nodes. A set of successor overlay links may be created for the set of successor files. The set of operating system network traffic may be routed using the set of successor overlay links in place of the set of original overlay links.

BACKGROUND

This disclosure relates generally to computer systems and, moreparticularly, relates to operating system update management for a sharedpool of configurable computing resources having a plurality of logicalpartitions (LPARs). The amount of data that needs to be managed byenterprises is increasing. System updates and data sharing for networknodes may be desired to be performed as efficiently as possible. As dataneeding to be managed increases, the need for efficient system updateand data sharing infrastructure may increase.

SUMMARY

Aspects of the disclosure relate to operating system update managementfor a shared pool of configurable computing resources having a pluralityof logical partitions (LPARs). A live kernel update operation may beused to update multiple logical partitions of a set of computingresources. The updated files may be shared across the logical partitionsafter block level modification to save disk space. A shared link may beused to establish individualized and shared regions for a set of filesof multiple LPARS. Modifications made to the individualized portion of afile may be applied to that specific file, while modifications made tothe shared portion may be synchronized and reflected in one or moreother files that are part of the shared link. Surrogate LPARs may becreated on an updated base operating system image using a set of overlaylinks to route operating system network traffic.

Disclosed aspects relate to operating system update management for ashared pool of configurable computing resources having a plurality oflogical partitions. An operating system update request may be received.A set of original shared portions and a set of original individualizedportions may be classified with respect to a set of original files on aset of original nodes. A set of original overlay links may be createdfor the set of original files. A set of operating system network trafficmay be routed using the set of original overlay links. A set ofsuccessor files may be established on a set of surrogate nodes. A set ofsuccessor overlay links may be created for the set of successor files.The set of operating system network traffic may be routed using the setof successor overlay links in place of the set of original overlaylinks.

The above summary is not intended to describe each illustratedembodiment or every implementation of the present disclosure.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The drawings included in the present application are incorporated into,and form part of, the specification. They illustrate embodiments of thepresent disclosure and, along with the description, serve to explain theprinciples of the disclosure. The drawings are only illustrative ofcertain embodiments and do not limit the disclosure.

FIG. 1 depicts a cloud computing node according to embodiments.

FIG. 2 depicts a cloud computing environment according to embodiments.

FIG. 3 depicts abstraction model layers according to embodiments.

FIG. 4 is a flowchart illustrating a method of operating system updatemanagement for a shared pool of configurable computing resources havinga plurality of logical partitions (LPARS), according to embodiments.

FIG. 5 shows an example system for operating system update managementfor a shared pool of configurable computing resources having a pluralityof logical partitions, according to embodiments.

FIG. 6 illustrates an example LPAR configuration for operating systemupdate management, according to embodiments.

FIG. 7 illustrates an example node and physical memory spaceconfiguration for operating system update management, according toembodiments.

FIG. 8 illustrates an example node and physical memory spaceconfiguration for operating system update management, according toembodiments.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention.

DETAILED DESCRIPTION

Aspects of the disclosure relate to operating system update managementfor a shared pool of configurable computing resources having a pluralityof logical partitions (LPARs). A live kernel update operation may beused to update multiple logical partitions of a set of computingresources. The updated files may be shared across the logical partitionsafter block level modification to save disk space. A shared link may beused to establish individualized (e.g., private) and shared regions fora set of files of multiple LPARS. Modifications made to theindividualized portion of a file may be applied to that specific file,while modifications made to the shared portion may be synchronized andreflected in one or more other files that are part of the shared link.Surrogate LPARs may be created on an updated base operating system imageusing a set of overlay links to route operating system network traffic.Leveraging private and shared regions for operating system updatemanagement may be associated with benefits including efficient diskspace usage, streamlined data sharing/transfer, and operating systemreliability.

System downtime and system resource utilization represent possiblechallenges related to managing operating system updates. Installingoperating system updates to logical partitions can often result insystem downtime (e.g., install time, machine restarts) as well asincreased disk usage as the size of operating systems increase (e.g.,due to additional service packs, patches, added technology levels).Accordingly, aspects of the disclosure relate to formatting logicalpartitions to have private and shared storage regions, such that datathat is common to multiple logical partitions (e.g., base operatingsystem images) can be shared between a plurality of logical partitions,while granular calibrations for each node may still be retained inprivate storage regions for each node. System operations for logicalpartitions may be transitioned from original nodes to surrogate nodesupon update completion to avoid system restarts and reduce systemdowntime. In this way, the amount of storage space needed for operatingsystem storage may be decreased (e.g., as multiple nodes share a singlebase operating system image on a shared physical memory space), andtime-efficient operating system updates may be facilitated.

Aspects of the disclosure include a method, system, and computer programproduct for a shared pool of configurable computing resources having aplurality of logical partitions (LPARS). Aspects of the disclosurerelate to initiating performance of a live kernel update (LKU) operationwith respect to a set of original files on an original set of originalnodes which have a set of original overlay links. An operating systemupdate request for the shared pool of configurable computing resourcesmay be received. A set of original shared portions and a set of originalindividualized portions may be classified with respect to a set oforiginal files on a set of original nodes. A respective original file ofthe set of original files may have a respective original shared portionand a respective original individualized portion. In embodiments, theset of original shared portions may include a set of original baseoperating system images. In embodiments, the set of originalindividualized portions may include a set of original technology levelsand a set of original service packs. Aspects of the disclosure relate tocreating a set of original overlay links for the set of original fileson the set of original nodes including a respective original overlaylink for the respective original file of the set of original files.Using the set of original overlay links, a set of operating systemnetwork traffic may be routed.

Aspects of the disclosure relate to establishing a set of successorfiles on a set of surrogate nodes to succeed the set of original fileson the set of original nodes. A first respective successor file of theset of successor files may map to a single successor shared storagesegment and a first respective successor individualized storage segment.A second respective successor file of the set of successor files may mapto the single successor shared storage segment and a second respectivesuccessor individualized storage segment. In embodiments, the singlesuccessor shared storage segment may include a single successor baseoperating system image which is common for the plurality of LPARs. Inembodiments, the first respective successor individualized storagesegment may include a first successor technology level, and the secondrespective successor individualized storage segment may include a secondsuccessor technology level which differs from the first successortechnology level. In embodiments, the first respective successorindividualized storage segment may include a first successor servicepack, and the second respective successor individualized storage segmentmay include a second successor service pack which differs from the firstsuccessor service pack.

Aspects of the disclosure relate to creating a set of successor overlaylinks for the set of successor files on the set of surrogate nodes. Theset of successor overlay links may include a shared overlay link whichmaps to the single successor shared storage segment, a first respectiveoverlay link which maps to the first respective successor individualizedstorage segment, and a second respective overlay link which maps to thesecond respective successor individualized storage segment. Inembodiments, performing the live kernel update operation may includeinvalidating the set of original overlay links, validating the set ofsuccessor overlay links, and freeing a chunk of storage corresponding tothe set of original files. The set of successor overlay links may beused to route the set of operating system network traffic in place ofthe set of original overlay links.

In embodiments, an original overlay link usage count may be incrementedfor each original overlay link of the set of original overlay links. Inembodiments, the original overlay link usage count may be decrementedfor each original overlay link of the set of original overlay linksswitched to the set of successor overlay links. In embodiments, inresponse to a live kernel update operation, it may be detected that theoriginal overlay link usage count has shrunk to zero. In response todetecting that the original overlay link usage count has shrunk to zero,the respective original shared portion of the respective original fileof the set of original files may be removed. In embodiments, the firstrespective successor individualized storage segment may be modifiedwithout modifying the second respective successor individualized storagesegment and without modifying the single successor shared storagesegment. Altogether, aspects of the disclosure can have performance orefficiency benefits (e.g., wear-rate, service-length, reliability,speed, flexibility, load balancing, responsiveness, stability, highavailability, resource usage, productivity). Aspects may save resourcessuch as bandwidth, disk, processing, or memory.

It is understood in advance that although this disclosure includes adetailed description on cloud computing, implementation of the teachingsrecited herein are not limited to a cloud computing environment. Rather,embodiments of the present invention are capable of being implemented inconjunction with any other type of computing environment now known orlater developed.

Cloud computing is a model of service delivery for enabling convenient,on-demand network access to a shared pool of configurable computingresources (e.g., networks, network bandwidth, servers, processing,memory, storage, applications, virtual machines, and services) that canbe rapidly provisioned and released with minimal management effort orinteraction with a provider of the service. This cloud model may includeat least five characteristics, at least three service models, and atleast four deployment models.

Characteristics are as follows:

On-demand self-service: a cloud consumer can unilaterally provisioncomputing capabilities, such as server time and network storage, asneeded automatically without requiring human interaction with theservice's provider.

Broad network access: capabilities are available over a network andaccessed through standard mechanisms that promote use by heterogeneousthin or thick client platforms (e.g., mobile phones, laptops, and PDAs).

Resource pooling: the provider's computing resources are pooled to servemultiple consumers using a multi-tenant model, with different physicaland virtual resources dynamically assigned and reassigned according todemand. There is a sense of location independence in that the consumergenerally has no control or knowledge over the exact location of theprovided resources but may be able to specify location at a higher levelof abstraction (e.g., country, state, or datacenter).

Rapid elasticity: capabilities can be rapidly and elasticallyprovisioned, in some cases automatically, to quickly scale out andrapidly released to quickly scale in. To the consumer, the capabilitiesavailable for provisioning often appear to be unlimited and can bepurchased in any quantity at any time.

Measured service: cloud systems automatically control and optimizeresource use by leveraging a metering capability at some level ofabstraction appropriate to the type of service (e.g., storage,processing, bandwidth, and active user accounts). Resource usage can bemonitored, controlled, and reported providing transparency for both theprovider and consumer of the utilized service.

Service Models are as follows:

Software as a Service (SaaS): the capability provided to the consumer isto use the provider's applications running on a cloud infrastructure.The applications are accessible from various client devices through athin client interface such as a web browser (e.g., web-based e-mail).The consumer does not manage or control the underlying cloudinfrastructure including network, servers, operating systems, storage,or even individual application capabilities, with the possible exceptionof limited user-specific application configuration settings.

Platform as a Service (PaaS): the capability provided to the consumer isto deploy onto the cloud infrastructure consumer-created or acquiredapplications created using programming languages and tools supported bythe provider. The consumer does not manage or control the underlyingcloud infrastructure including networks, servers, operating systems, orstorage, but has control over the deployed applications and possiblyapplication hosting environment configurations.

Infrastructure as a Service (IaaS): the capability provided to theconsumer is to provision processing, storage, networks, and otherfundamental computing resources where the consumer is able to deploy andrun arbitrary software, which can include operating systems andapplications. The consumer does not manage or control the underlyingcloud infrastructure but has control over operating systems, storage,deployed applications, and possibly limited control of select networkingcomponents (e.g., host firewalls).

Deployment Models are as follows:

Private cloud: the cloud infrastructure is operated solely for anorganization. It may be managed by the organization or a third party andmay exist on-premises or off-premises.

Community cloud: the cloud infrastructure is shared by severalorganizations and supports a specific community that has shared concerns(e.g., mission, security requirements, policy, and complianceconsiderations). It may be managed by the organizations or a third partyand may exist on-premises or off-premises.

Public cloud: the cloud infrastructure is made available to the generalpublic or a large industry group and is owned by an organization sellingcloud services.

Hybrid cloud: the cloud infrastructure is a composition of two or moreclouds (private, community, or public) that remain unique entities butare bound together by standardized or proprietary technology thatenables data and application portability (e.g., cloud bursting forloadbalancing between clouds).

A cloud computing environment is service oriented with a focus onstatelessness, low coupling, modularity, and semantic interoperability.At the heart of cloud computing is an infrastructure comprising anetwork of interconnected nodes.

Referring now to FIG. 1, a block diagram of an example of a cloudcomputing node is shown. Cloud computing node 100 is only one example ofa suitable cloud computing node and is not intended to suggest anylimitation as to the scope of use or functionality of embodiments of theinvention described herein. Regardless, cloud computing node 100 iscapable of being implemented and/or performing any of the functionalityset forth hereinabove.

In cloud computing node 100 there is a computer system/server 110, whichis operational with numerous other general purpose or special purposecomputing system environments or configurations. Examples of well-knowncomputing systems, environments, and/or configurations that may besuitable for use with computer system/server 110 include, but are notlimited to, personal computer systems, server computer systems, tabletcomputer systems, thin clients, thick clients, handheld or laptopdevices, multiprocessor systems, microprocessor-based systems, set topboxes, programmable consumer electronics, network PCs, minicomputersystems, mainframe computer systems, and distributed cloud computingenvironments that include any of the above systems or devices, and thelike.

Computer system/server 110 may be described in the general context ofcomputer system executable instructions, such as program modules, beingexecuted by a computer system. Generally, program modules may includeroutines, programs, objects, components, logic, data structures, and soon that perform particular tasks or implement particular abstract datatypes. Computer system/server 110 may be practiced in distributed cloudcomputing environments where tasks are performed by remote processingdevices that are linked through a communications network. In adistributed cloud computing environment, program modules may be locatedin both local and remote computer system storage media including memorystorage devices.

As shown in FIG. 1, computer system/server 110 in cloud computing node100 is shown in the form of a general-purpose computing device. Thecomponents of computer system/server 110 may include, but are notlimited to, one or more processors or processing units 120, a systemmemory 130, and a bus 122 that couples various system componentsincluding system memory 130 to processing unit 120.

Bus 122 represents one or more of any of several types of busstructures, including a memory bus or memory controller, a peripheralbus, an accelerated graphics port, and a processor or local bus usingany of a variety of bus architectures. By way of example, and notlimitation, such architectures include Industry Standard Architecture(ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA)bus, Video Electronics Standards Association (VESA) local bus, andPeripheral Component Interconnect (PCI) bus.

Computer system/server 110 typically includes a variety of computersystem readable media. Such media may be any available media that isaccessible by computer system/server 110, and it includes both volatileand non-volatile media, removable and non-removable media. An example ofremovable media is shown in FIG. 1 to include a Digital Video Disc (DVD)192.

System memory 130 can include computer system readable media in the formof volatile or non-volatile memory, such as firmware 132. Firmware 132provides an interface to the hardware of computer system/server 110.System memory 130 can also include computer system readable media in theform of volatile memory, such as random access memory (RAM) 134 and/orcache memory 136. Computer system/server 110 may further include otherremovable/non-removable, volatile/non-volatile computer system storagemedia. By way of example only, storage system 140 can be provided forreading from and writing to a non-removable, non-volatile magnetic media(not shown and typically called a “hard drive”). Although not shown, amagnetic disk drive for reading from and writing to a removable,non-volatile magnetic disk (e.g., a “floppy disk”), and an optical diskdrive for reading from or writing to a removable, non-volatile opticaldisk such as a CD-ROM, DVD-ROM or other optical media can be provided.In such instances, each can be connected to bus 122 by one or more datamedia interfaces. As will be further depicted and described below,memory 130 may include at least one program product having a set (e.g.,at least one) of program modules that are configured to carry out thefunctions described in more detail below.

Program/utility 150, having a set (at least one) of program modules 152,may be stored in memory 130 by way of example, and not limitation, aswell as an operating system, one or more application programs, otherprogram modules, and program data. Each of the operating system, one ormore application programs, other program modules, and program data orsome combination thereof, may include an implementation of a networkingenvironment. Program modules 152 generally carry out the functionsand/or methodologies of embodiments of the invention as describedherein.

Computer system/server 110 may also communicate with one or moreexternal devices 190 such as a keyboard, a pointing device, a display180, a disk drive, etc.; one or more devices that enable a user tointeract with computer system/server 110; and/or any devices (e.g.,network card, modem, etc.) that enable computer system/server 110 tocommunicate with one or more other computing devices. Such communicationcan occur via Input/Output (I/O) interfaces 170. Still yet, computersystem/server 110 can communicate with one or more networks such as alocal area network (LAN), a general wide area network (WAN), and/or apublic network (e.g., the Internet) via network adapter 160. Asdepicted, network adapter 160 communicates with the other components ofcomputer system/server 110 via bus 122. It should be understood thatalthough not shown, other hardware and/or software components could beused in conjunction with computer system/server 110. Examples, include,but are not limited to: microcode, device drivers, redundant processingunits, external disk drive arrays, Redundant Array of Independent Disk(RAID) systems, tape drives, data archival storage systems, etc.

Referring now to FIG. 2, illustrative cloud computing environment 200 isdepicted. As shown, cloud computing environment 200 comprises one ormore cloud computing nodes 100 with which local computing devices usedby cloud consumers, such as, for example, personal digital assistant(PDA) or cellular telephone 210A, desktop computer 210B, laptop computer210C, and/or automobile computer system 210N may communicate. Nodes 100may communicate with one another. They may be grouped (not shown)physically or virtually, in one or more networks, such as Private,Community, Public, or Hybrid clouds as described hereinabove, or acombination thereof. This allows cloud computing environment 200 tooffer infrastructure, platforms and/or software as services for which acloud consumer does not need to maintain resources on a local computingdevice. It is understood that the types of computing devices 210A-Nshown in FIG. 2 are intended to be illustrative only and that computingnodes 100 and cloud computing environment 200 can communicate with anytype of computerized device over any type of network and/or networkaddressable connection (e.g., using a web browser).

Referring now to FIG. 3, a set of functional abstraction layers providedby cloud computing environment 200 in FIG. 2 is shown. It should beunderstood in advance that the components, layers, and functions shownin FIG. 3 are intended to be illustrative only and the disclosure andclaims are not limited thereto. As depicted, the following layers andcorresponding functions are provided.

Hardware and software layer 310 includes hardware and softwarecomponents. Examples of hardware components include mainframes, in oneexample IBM System z systems; RISC (Reduced Instruction Set Computer)architecture based servers, in one example IBM System p systems; IBMSystem x systems; IBM BladeCenter systems; storage devices; networks andnetworking components. Examples of software components include networkapplication server software, in one example IBM Web Sphere® applicationserver software; and database software, in one example IBM DB2® databasesoftware. IBM, System z, System p, System x, BladeCenter, WebSphere, andDB2 are trademarks of International Business Machines Corporationregistered in many jurisdictions worldwide.

Virtualization layer 320 provides an abstraction layer from which thefollowing examples of virtual entities may be provided: virtual servers;virtual storage; virtual networks, including virtual private networks;virtual applications and operating systems; and virtual clients.

In one example, management layer 330 may provide the functions describedbelow. Resource provisioning provides dynamic procurement of computingresources and other resources that are utilized to perform tasks withinthe cloud computing environment. Metering and Pricing provide costtracking as resources are utilized within the cloud computingenvironment, and billing or invoicing for consumption of theseresources. In one example, these resources may comprise applicationsoftware licenses. Security provides identity verification for cloudconsumers and tasks, as well as protection for data and other resources.User portal provides access to the cloud computing environment forconsumers and system administrators. Service level management providescloud computing resource allocation and management such that requiredservice levels are met. Service Level Agreement (SLA) planning andfulfillment provide pre-arrangement for, and procurement of, cloudcomputing resources for which a future requirement is anticipated inaccordance with an SLA. A cloud manager 350 is representative of a cloudmanager (or shared pool manager) as described in more detail below.While the cloud manager 350 is shown in FIG. 3 to reside in themanagement layer 330, cloud manager 350 can span all of the levels shownin FIG. 3, as discussed below.

Workloads layer 340 provides examples of functionality for which thecloud computing environment may be utilized. Examples of workloads andfunctions which may be provided from this layer include: mapping andnavigation; software development and lifecycle management; virtualclassroom education delivery; data analytics processing; transactionprocessing; and operating system update management 360, which may beutilized as discussed in more detail below.

FIG. 4 is a flowchart illustrating a method 400 of operating systemupdate management for a shared pool of configurable computing resourceshaving a plurality of logical partitions (LPARS). Aspects of FIG. 4relate to dynamically (e.g., in real-time, ongoing, on-the-fly)initiating performance of a live kernel update (LKU) operation to updatemultiple logical partitions of a set of computing resources. The livekernel update operation may be performed with respect to a set oforiginal files on a set of original nodes. The set of original nodes caninclude logical partitions, virtual machines, or other emulated computersystem environments based on computer architectures and configured toperform one or more tasks or functions. In embodiments, the set oforiginal nodes can include subsets of a computer's hardware resourcesthat are virtualized as a separate computer and configured to provide acomplete system platform and operating system environment for programexecution. In embodiments, the set of original nodes may include a setof original files having individualized and shared portions. Leveragingindividualized (e.g., private) and shared regions for operating systemupdate management may be associated with benefits including efficientdisk space usage, streamlined data sharing/transfer, and operatingsystem reliability. The method 400 may begin at block 401.

In embodiments, the receiving, the classifying, the creating, therouting, the establishing, the creating, the routing, and other stepsdescribed herein may each occur in an automated fashion without userintervention at block 404. In embodiments, the receiving, theclassifying, the creating, the routing, the establishing, the creating,the routing, and other steps described herein may be carried out by aninternal operating system update management module maintained in apersistent storage device of the shared pool of configurable computingresources (e.g., database, central management server). In certainembodiments, the receiving, the classifying, the creating, the routing,the establishing, the creating, the routing, and other steps describedherein may be carried out by an external operating system updatemanagement module hosted by a remote computing device or server (e.g.,accessible via a subscription, usage-based, or other service model). Inthis way, aspects of operating system update management may be performedusing automated computing machinery without manual action. Other methodsof performing the steps described herein are also possible.

At block 410, an operating system update request may be received for theshared pool of configurable computing resources. Generally, receivingcan include detecting, collecting, recognizing, acquiring, sensing, orotherwise accepting delivery of the operating system update request. Inembodiments, the operating system update request may include a set ofcomputer instructions seeking permission or authorization to amend,renew, add features, or otherwise upgrade one or more aspects of thesoftware environment of the shared pool of computing resources. Theoperating system update request may include an error fix, securitypatch, version renewal, performance/usability improvement, or other typeof update with respect to a base operating system, technology level,service pack, or other aspect of the software environment of the sharedpool of computing resources. As an example, receiving the operatingsystem update request may include accepting a notification of a pendingsoftware version update to a shared base software platform of the sharedpool of computing resources, as well as a set of individual servicepacks for a set of logical partitions (e.g., each service pack targets adifferent logical partition). Other methods of receiving the operatingsystem update request are also possible.

At block 420, a set of original shared portions and a set of originalindividualized portions may be classified with respect to a set oforiginal files on the set of original nodes. A respective original fileof the set of original files may have a respective original sharedportion and a respective original individualized portion. Generally,classifying can include categorizing, organizing, labeling, formatting,structuring, or otherwise arranging the set of original shared portionsand the set of original individualized portions. Aspects of thedisclosure relate to the recognition that, in certain situations, it maybe desirable to maintain a common (e.g., shared) base operating systembetween a set of logical partitions while reserving a private (e.g.,individualized) data space of each logical partition for use by servicepacks, technology levels, and other software specific to a certainlogical partition. Accordingly, aspects of the disclosure relate toclassifying a set of original shared portions and a set of originalindividualized portions for a set of original files. The set of originalfiles may include a collection of related data or program records storedon an original node (e.g., logical partition). In embodiments,classifying may include formatting the set of original files (e.g., arespective original file for each original node) to create a firstpartition corresponding to the original shared portion and a secondpartition corresponding to the respective original individualizedportion (e.g., such that each original node has a respective originalfile including an original shared portion and an original individualizedportion). Other methods of classifying the set of original files arealso possible.

As described herein, the set of original files may be classified to havea set of original shared portions and a set of original individualizedportions. The set of original shared portions may include segments orregions of an original file that are designated for use by data orapplications common between one or more original nodes. In embodiments,the set of original shared portions may include separate physicaladdress spaces (e.g., local storage, communicatively connected storagedevices, remote storage) for each respective original node that areconfigured to maintain data shared by the set of original nodes. Forinstance, the set of original shared portions may be used to store a setof original base operating system images for the set of original nodes.The set of original base operating system images may include serializedcopies or reproductions of the files that constitute the corefunctionality of an original node (e.g., software responsible formanaging hardware and software resources to facilitate systemoperation). In embodiments, the set of original base operating systemimages may be common between the set of original nodes (e.g., eachoriginal node uses the same operating system version, such as softwareversion 7.1.x.x). In certain embodiments, each original node of the setof original nodes may maintain a copy of the base operating system imagein local storage (e.g., stored on the original node itself). Inembodiments, each original node of the set of original nodes maymaintain the base operating system image in a separate physical memorystorage unit at set of data blocks/addresses designated for sharedstorage. In this way, the set of original shared portions may be used tofacilitate storage of data and applications common to the set oforiginal nodes (e.g., data may be saved in the same physical memoryspace or different physical spaces while remaining common between theset of original nodes.)

In embodiments, the set of original files may include a set of originalindividualized portions. As described herein, aspects of the disclosurerelate to the recognition that, in certain situations, it may bedesirable to modify or customize one or more aspects of an individuallogical partition without making changes to the base operating system orother common data shared by the entire set of original nodes.Accordingly, aspects of the disclosure relate to a set of originalindividualized portions for maintaining data or information that onlyapplies to a particular original node. Generally, the set ofindividualized portions may include segments or regions of an originalfile that are designated for use by data or applications specificallyconfigured for a particular original node. In embodiments, the set oforiginal individualized portions may be used to store a set of originaltechnology levels. The set of original technology levels may include agroup of software fixes and new features added to the softwareenvironment of an original node. The set of original technology levelsmay be used to provide new functionality or deliver error fixes. Inembodiments, the set of original individualized portions may be used tostore a set of service packs. The set of service packs may include acollection of updates, fixes, or enhancements delivered in the form of asingle installable package to a particular original node. As describedherein, the set of original individualized portions may be used to storedifferent technology levels and service packs for different originalnodes. In this way, a common base operating system may be shared acrossthe set of original nodes (e.g., via the set of original sharedportions) while maintaining different fine-grained calibrations for eachindividual original node (e.g., via the set of original individualizedportions). As an example, a set of original nodes may include a firstoriginal node with a software version of 7.1.0.1, a second original nodewith a software version of 7.1.0.4 and a third original node with asoftware version of 7.1.0.6 (e.g., where 7.1. represents the baseoperating system, and the subsequent decimal places represent minorversion differences). Other methods of classifying the set of originalfiles and using the set of original individualized portions and the setof original shared portions are also possible.

At block 430, a set of original overlay links may be created for the setof original files on the set of original nodes. The set of overlay linksmay include a respective original overlay link for the respectiveoriginal file of the set of original files. Generally, creating caninclude generating, constructing, setting-up, instantiating, orproducing the set of overlay links. Aspects of the disclosure relate tothe recognition that, in embodiments, it may be desirable to generate aback-up image of the operating system of a set of original nodestogether with logical mappings used by the set of original nodes foraccessing operating system files and routing data traffic (e.g., priorto an operating system update). Accordingly, aspects of the disclosurerelate to creating a set of overlay links to facilitate communicationbetween one or more original nodes and one or more physical memoryspaces (e.g., maintaining operating system files for the set of originalnodes). The set of overlay links may include intermediary logicalelements configured to indicate the saved location of data orinformation on the physical memory spaces (e.g., local storage, remotestorage, connected storage devices). As examples, the set of overlaylinks may include pointers, indicators, addresses, or mappings thatdesignate the location of particular data files on one or more physicalmemory spaces. In embodiments, creating may include mapping a particulardata file on a physical memory space with an associated memory address,and registering the memory address in a network logical topologydatabase accessible by the set of original nodes (e.g., such that one ormore original nodes may use the memory address to access the data file).Other methods of creating the set of original overlay links are alsopossible.

At block 440, a set of operating system network traffic may be routedusing the set of original overlay links. Generally, routing can includedirecting, conveying, transmitting, sending, or conducting the set ofoperating system traffic network. The set of operating system networktraffic may include data packets, program commands, softwareinstructions, and other types of communication carried out between oneor more original nodes of the set of original nodes and the physicalmemory space. Routing may include facilitating access by the set oforiginal nodes to data or information saved on one or more physicalmemory spaces. In embodiments, routing can include requesting aparticular data file (e.g., an original node seeking a file from aphysical memory space), and using the set of original overlay links toidentify the saved location and access the particular data file. As anexample, a particular original node of the set of original nodes mayspecify a request for a program data file corresponding to a networkdiagnostic tool. The particular original node may search a networklogical topology database to identify an associated memory address forthe desired program data file, and utilize the set of original overlaylinks to access and read the program data file from the correspondingmemory address of the physical memory space. Other methods of routingthe set of operating system network traffic using the set of originaloverlay links are also possible.

At block 450, a set of successor files may be established on a set ofsurrogate nodes to succeed the set of original files on the set oforiginal nodes. Generally, establishing can include providing,generating, instantiating, placing, deploying, setting-up, implementing,or instituting the set of successor files on the set of surrogate nodes.Aspects of the disclosure relate to the recognition that, in somesituations, generating a reproduction of the set of original files andthe set of original nodes may be associated with streamlined updateperformance for a shared pool of computing resources (e.g., updates maybe performed on the duplicated files/nodes, and LPAR system operationsmay be switched over upon update completion to avoid system restarts).The set of surrogate nodes may include virtualized duplicates,reproductions, copies, or substitutes of the set of original nodes. Theset of surrogate nodes may maintain the same operating configuration,system parameters, and other characteristics of the set of originalnodes. In embodiments, establishing the set of successor files on theset of surrogate nodes may include creating a new logical partition foreach original node of the set of original nodes, and replicating thesystem configuration of each respective original node on a correspondingsurrogate node. As described herein, the set of surrogate nodes mayinclude a set of successor files to succeed (e.g., follow, come after,replace) the set of original files. In embodiments, the set of successorfiles may include reproductions or copies of the set of original files,and may be maintained on the set of surrogate nodes. In certainembodiments, the set of successor files may be configured to receive oneor more operating system updates (e.g., based on the operating systemupdate request). Other methods of establishing the set of successorfiles on the set of surrogate nodes are also possible.

In embodiments, aspects of the disclosure relate to the recognition thatuse of a single shared memory space (e.g., single physical memorydevice) for the set of surrogate nodes may be associated with benefitsincluding operating system update efficiency and reduced disk storageuse (e.g., as multiple nodes are configured to share the same datafiles). Accordingly, aspects of the disclosure relate to establishing aset of successor files configured to map to a single successor sharedstorage segment (e.g., that maintains data common to the set ofsurrogate nodes) as well as respective successor individualized storageelements (e.g., that maintain data particularly configured for certainsurrogate nodes). In embodiments, one or more respective successor filesof the set of successor files may map to a single successor sharedstorage segment. The single successor shared storage segment may includea unified memory space (e.g., database, storage device) configured tomaintain data and information shared by the set of surrogate nodes. Asan example, the single successor shared storage segment may include acentral storage server configured to maintain a single successor baseoperating system image that is common for a plurality of logicalpartitions. The single successor base operating system image may includea copy or reproduction of an operating system that is configured to beaccessed and shared by the set of surrogate nodes (e.g., multiplesurrogate nodes may access the same OS files on the same physical memoryspace). In certain embodiments, the single successor base operatingimage may include an updated software version of the operating systemwith respect to the original base OS images of the set of original nodes(e.g., successor OS image having software version 7.2.0.0 versusoriginal OS image having software version 7.1.0.0). Other types and usesfor the single successor shared storage segment are also possible.

In embodiments, one or more successor files of the set of successorfiles may map to a respective successor individualized storage segment.As described herein, aspects of the disclosure relate to the recognitionthat in certain situations, it may be desirable to modify or customizeone or more aspects of an individual logical partition (e.g., surrogatenode) without making changes to the base operating system shared by theentire set of surrogate nodes (e.g., base OS image maintained on thesingle shared storage segment). Accordingly, aspects of the disclosurerelate to a set of respective successor individualized storage segmentsfor maintaining data or information that applies to a particularsurrogate node. Generally, the set of respective successorindividualized storage segments may include portions or regions of ashared memory device that are designated for use by data or applicationsspecific to a particular surrogate node. In embodiments, the set ofrespective successor individualized storage segments may include a setof successor technology levels. The set of successor technology levelsmay include a group of software fixes and new features added to thesoftware environment of a surrogate node. The set of successortechnology levels may include updated or revised technology levels withrespect to the set of original technology levels. In embodiments, theset of successor technology levels may differ for one or more respectivesuccessor individualized storage segments. As an example, a firstrespective successor individualized storage segment may include a firstsuccessor technology level (e.g., technology level 3.4) and a secondrespective successor individualized storage segment may include a secondsuccessor technology level (e.g., technology level 8.2).

In embodiments, the set of respective successor individualized storagesegments may include a set of successor service packs. Generally, theset of service packs may include a collection of updates, fixes, orenhancements delivered in the form of a single installable package to aparticular surrogate node. The set of successor service packs mayinclude updated software versions with respect to the set of originalservice packs. As described herein, the set of respective successorindividualized storage segments may be used to store different servicepacks for different surrogate nodes. As an example, a first respectivesuccessor individualized storage segment may include a first successorservice pack (e.g., 5.1.0.6) and a second respective successorindividualized storage segment may include a second successor servicepack (e.g., 5.1.0.1). Other types and uses for the set of respectivesuccessor individualized storage segments are also possible.

At block 460, a set of successor overlay links may be created for theset of successor files on the set of surrogate nodes. Generally,creating can include generating, constructing, setting-up,instantiating, or producing the set of successor overlay links. Aspectsof the disclosure relate to the recognition that, subsequent toestablishment of the set of successor files on the set of surrogatenodes, it may be desirable to arrange (e.g., remap) a set of successor(e.g., new) overlay links to facilitate data communication between theset of surrogate nodes, single successor shared storage segment, andrespective successor individualized storage segments (e.g., create newnetwork paths to access data on a shared physical memory space). The setof successor overlay links may include pointers, indicators, addresses,mappings or other logical elements that designate the location ofparticular data files on a physical memory space. For instance, the setof successor overlay links may specify the network path and savedlocation of a data file stored in the single successor shared storagesegment or a respective successor individualized storage segment. Inembodiments, creating the set of successor overlay links may includegenerating a logical topology map of the network, and designating (e.g.,highlighting, tagging, marking) a subset of network paths to connect theset of successor files on the set of surrogate nodes with a physicalmemory space including the single successor shared storage segment andthe set of respective successor individualized storage segments. In thisway, continuous file availability (e.g., of operating system images) maybe maintained for a set of logical partitions throughout an operatingsystem update. Other methods of creating the set of successor overlaylinks are also possible.

In embodiments, aspects of the disclosure relate to using a set ofsuccessor overlay links to facilitate data communication between a setof surrogate nodes and a single physical memory space having a singlesuccessor shared storage segment (e.g., for storage of data common tothe set of surrogate nodes) and a plurality of respective successorindividualized storage segments (e.g., for storage of data particularlyconfigured for a certain surrogate node). In embodiments, the set ofsuccessor overlay links may include a successor shared overlay linkwhich maps to the single shared storage segment. The successor sharedoverlay link may include a network path map or memory address configuredto indicate the location of data on the single shared storage segmentfor access by the set of surrogate nodes. In embodiments, the successorshared overlay link may connect shared data on the single shared storagesegment with each successor node of the set of successor nodes. Inembodiments, the set of successor links may include a first respectiveoverlay link which maps to the first respective successor individualizedstorage segment and a second respective overlay link which maps to thesecond respective successor individualized storage segment. As describedherein, aspects of the disclosure relate to maintaining a set ofrespective successor individualized storage segments for maintainingdata that particularly applies to or is configured for a certainsurrogate node. Accordingly, a plurality (e.g., first and second)respective overlay links may be used to facilitate data transfer betweenrespective successor individualized storage segments and correspondingsurrogate nodes of the set of compute nodes. Other types of successoroverlay links are also possible.

In embodiments, the set of original overlay links may be invalidated,the set of overlay links may be validated, and storage may be freed atblock 462. Aspects of the disclosure relate to the recognition that,upon transitioning system operations from the set of original nodes tothe set of surrogate nodes, operating system network traffic may berouted using the set of successor overlay links such that the set oforiginal overlay links may no longer be necessary. Accordingly, inembodiments, the set of original overlay links may be invalidated.Invalidating can include deleting, abolishing, removing, nullifying, orotherwise suspending usage of the set of original overlay links. Forinstance, invalidating may include removing a set of network addressesassociated with the set of original overlay links from a central logicaltopology database. As described herein, transitioning system operationsto the set of surrogate nodes may include utilizing the set of successoroverlay links. Accordingly, in embodiments, the set of successor overlaylinks may be validated. Validating can include verifying,authenticating, authorizing, or otherwise configuring the set ofsuccessor overlay links for usage. As an example, validating may includeidentifying data entries corresponding to the set of successor overlaylinks in a network logical topology database and marking them with a tagthat indicates they are ready for use. Other methods of invalidating theset of original overlay links and validating the set of successoroverlay links are also possible.

In embodiments, a chunk of storage corresponding to the set of originalfiles may be freed. Generally, freeing can include clearing, releasing,deleting, or otherwise opening up a portion of storage spacecorresponding to the set of original files (e.g., cleaning a space).Aspects of the disclosure relate to the recognition that by making useof a single shared physical memory space for the set of surrogate nodes,multiple nodes may access and use the same data (e.g., same copy of anoperating system image). Accordingly, disk storage space occupied by theset of original files (e.g., original base OS images) may be cleared foruse by other data and applications. In embodiments, freeing the chunk ofstorage may include identifying a portion of data corresponding to theset of original files, and deleting it from memory. Consider thefollowing example. A set of original nodes may include a first originalnode, a second original node, and a third original node. Each node ofthe set of original nodes may maintain an individual copy of an originalbase OS image on local storage (e.g., for a 20 gigabyte operatingsystem, a total of 60 gigabytes may be used for operating system storagebetween the three original nodes). As described herein, the a set ofsuccessor files on a set of surrogate nodes may be established, and theset of surrogate nodes may share a single successor base OS imagemaintained on a single successor shared storage segment. Accordingly, inembodiments, the original base OS images maintained in local storage bythe set of original nodes may be deleted to clear up storage space foruse by other data and applications (e.g., such that a total of 20gigabytes is used for operating system storage between the threesurrogate nodes). Other methods of freeing a chunk of storage are alsopossible.

At block 470, the set of operating system network traffic may be routedusing the set of successor overlay links in place of the set of originaloverlay links. Generally, routing can include directing, conveying,transmitting, sending, or conducting the set of operating system trafficnetwork. The set of operating system network traffic may include datapackets, program commands, software instructions, and other types ofcommunication carried out between one or more logical partitions and aphysical memory space. As described herein, aspects of the disclosurerelate to transitioning system operations of a set of logical partitionsto a set of surrogate nodes that are configured to use a set ofsuccessor overlay links for data communication with a physical memoryspace. Accordingly, upon transition to the set of surrogate nodes, theset of original overlay links may be replaced with the set of successoroverlay links, such that data communication performed between thephysical memory space and the set of surrogate nodes is carried outusing the set of successor overlay links. In embodiments, routing mayinclude facilitating access by the set of surrogate nodes to data orinformation saved on a shared physical memory space. As an example, afirst surrogate node of the set of surrogate nodes may specify an accessrequest for a base operating system file (e.g., stored on the singlesuccessor shared storage segment) as well as a service pack file (e.g.,stored on a first respective successor individualized storage segment).Accordingly, the first surrogate node may utilize the successor sharedoverlay link to access the base operating system file on the singlesuccessor shared storage segment and the first respective successoroverlay link to access the service pack file on the first respectivesuccessor individualized storage segment. Other methods of routing theset of operating system network traffic using the set of successoroverlay links are also possible.

Consider the following example. A cloud computing environment mayinclude a set of original nodes having a first original node, a secondoriginal node, and a third original node. Each original node may have anoriginal shared portion (e.g., local storage, connected storage device)maintaining an individual copy of an original base operating system. Theoriginal base operating system may be a software version 7.1.x.x, and becommon between the set of original nodes. In embodiments, each originalnode may maintain service packs and technology levels in a set oforiginal individualized portions. As described herein, the cloudcomputing environment may receive an operating system update request forthe set of original nodes. In embodiments, a set of original overlaylinks may be created to record the logical mappings between the set oforiginal nodes, the set of original shared portions, and the set oforiginal individualized portions. The set of original overlay links maybe used to route operating system traffic between the set of originalnodes, the set of original shared portions, and the set of originalindividualized portions.

As described herein, aspects of the disclosure relate to performing theoperating system update with respect to a set of surrogate nodes, andtransitioning system operations from the original set of nodes to theset of surrogate nodes. In embodiments, the set of surrogate nodes maybe established by creating virtual duplicates of the set of or originalnodes. For instance, a first surrogate node may be created as a copy ofthe first original node, a second surrogate node may be created as acopy of the second original node, and a third surrogate node may becreated as a copy of the third original node. As described herein, theset of surrogate nodes may include a set of successor files. Eachsuccessor file may map to a single successor shared storage segment andone or more respective successor individualized storage segments uniqueto particular successor nodes. In embodiments, the single successorshared storage segment may be stored on a physical memory device that isuniversally accessible to the set of surrogate nodes. In embodiments, asuccessor base OS image (e.g., updated version of the base operatingsystem) may be installed to the single successor shared storage segment.For instance, the successor base OS image may include an operatingsystem software version of 7.2.xx. The successor base OS image may beshared by each node of the set of successor nodes (e.g., a single copyof the successor base OS image is common between the set of successornodes).

In embodiments, as described herein, each successor file of the set ofsuccessor files may map to one or more respective individualized storagesegments. In embodiments, the set of respective individualized storagesegments may be configured to maintain technology levels, service packs,or other software features that are particular to a certain surrogatenode. For instance, a first successor file of the first surrogate nodemay map to a first respective individualized storage segment thatmaintains a first service pack, a second successor file of the secondsurrogate node may map to a second respective individualized storagesegment that maintains a second service pack, and a third successor fileof the third surrogate node may map to a third respective individualizedstorage segment that maintains a third technology level. In embodiments,a set of successor overlay links may be created to record the logicalmappings between the set of surrogate nodes, the single successor sharedstorage segment, and the set of respective successor individualizedstorage segments. The set of successor overlay links may be used toroute operating system traffic between the set of surrogate nodes, thesingle successor shared storage segment, and the set of respectivesuccessor individualized storage segments. Accordingly, systemoperations for the logical partitions may be transitioned to the set ofsurrogate nodes and continue using the updated base OS image.

Method 400 concludes at block 499. As described herein, aspects ofmethod 400 relate to dynamically (e.g., in real-time, ongoing,on-the-fly) initiating performance of a live kernel update (LKU)operation to update multiple logical partitions of a set of computingresources. Aspects of method 400 may provide performance or efficiencybenefits for operating system update management. For example, use of asingle successor shared storage segment may reduce the amount of memoryspace required for operating system storage (e.g., multiple logicalpartitions share the same base OS image). As another example, transitionof system operations from a set of original nodes to a set of surrogatenodes having a successor base OS image (e.g., updated operating systemversion) may be associated with streamlined update installation for aset of logical partitions (e.g., the need for system restarts may beavoided.) Altogether, leveraging individualized (e.g., private) andshared regions for operating system update management may be associatedwith benefits including efficient disk space usage, streamlined datasharing/transfer, and operating system reliability.

FIG. 5 shows an example system 500 for operating system updatemanagement for a shared pool of configurable computing resources havinga plurality of logical partitions, according to embodiments. Aspects ofFIG. 5 relate to initiating performance of a live kernel update (LKU)operation to update multiple logical partitions of a set of computingresources. The example system 500 may include a processor 506 and amemory 508 to facilitate implementation of operation system updatemanagement. The example system 500 may include a database 502 (e.g.,operating system management database) configured to providenotifications and alerts of pending operating system updates to logicalpartitions. In embodiments, the example system 500 may include anoperating system (OS) update management system 510. The OS updatemanagement system may be communicatively connected to the database 502,and be configured to receive data 504 (e.g., operating system updaterequest) related to operating system updates. The OS update managementsystem may include a receiving module 515 configured to receive anoperating system update request, a classifying module 520 configured toclassify a set of original shared portions and a set of originalindividualized portions with respect to a set of original files on a setof original nodes, a first creating module 525 configured to create aset of original overlay links for the set of original files on the setof original nodes, a first routing module 530 configured to route a setof operating system network traffic using the set of original overlaylinks, an establishing module 535 configured to establish a set ofsuccessor files on a set of surrogate nodes, a second creating module540 to create a set of successor overlay links for the set of successorfiles, and a second routing block 545 to route the set of operatingsystem network traffic using the set of successor overlay links. Theoperational steps described herein may be performed dynamically (e.g.,in real-time, ongoing, on-the-fly) to streamline operating system updatemanagement. The OS update management system 510 may be communicativelyconnected with a module management system 550 that includes one or moremodules for implementing aspects of operating system update management.

In embodiments, an original overlay link usage count may be incrementedat module 551. The overlay link usage count may be incremented for eachoriginal overlay link of the set of original overlay links. Generally,incrementing can include raising, advancing, or increasing the overlaylink usage count. Aspects of the disclosure, in certain embodiments,relate to maintaining an isolated link reference count to record thenumber of overlay links in use by a set of logical partitions. Inembodiments, incrementing the overlay link usage count may includeadding one to the overlay link usage count for each original overlaylink that is created. As an example, consider a set of logicalpartitions that has a total of 12 original overlay links. Accordingly,the link usage count (e.g., isolated link reference count) may indicatea value of “12” to reflect that there are 12 original overlay links inuse. In response to creation of a new original overlay link, the linkusage count may be incremented from “12” to “13” to record the increaseto the number of original overlay links. Other methods of incrementingthe original overlay link usage count are also possible.

In embodiments, the original overlay link usage count may be decrementedat module 552. The overlay link usage count may be decremented for eachoriginal overlay link of the set of original overlay links that isswitched to the set of successor overlay links. Generally, decrementingcan include decreasing, lessening, lowering, or otherwise reducing theoverlay link usage count. Aspects of the disclosure, in certainembodiments, relate to the recognition that as system operations for aset of logical partitions transition to a set of surrogate nodes, theset of original overlay links may be replaced with a set of successoroverlay links. Accordingly, aspects of the disclosure relate to updatingthe original overlay link usage count to reflect the number of originaloverlay links that remain active. In embodiments, decrementing theoverlay link usage count may include removing one from the overlay linkusage count for each original overlay link that is switched to asuccessor overlay link. As an example, consider a set of logicalpartitions that has a total of 21 original overlay links. Accordingly,the link usage count may indicate a value of “21” to reflect that thereare 21 original overlay links in use. In response to switching anoriginal overlay link to a successor overlay link (e.g., invalidatingthe original overlay link and validating the corresponding successoroverlay link), the link usage count may be reduced from “21” to “20” torecord the decrease to the number of original overlay links. Othermethods of incrementing the original overlay link usage count are alsopossible.

In embodiments, the original overlay link usage count may be reduced andan original shared portion of the set of original files may be removedat module 553. In embodiments, in response to a live kernel update (LKU)operation, it may be detected that the original overlay link usage counthas shrunk to zero. Generally, detecting can include sensing,recognizing, identifying, discovering, or otherwise ascertaining thatthe original overlay link usage count has shrunk to zero. Inembodiments, detecting may include consulting a network logical topologydatabase and ascertaining that all of the original overlay links havebeen transitioned to successor overlay links, and that the link usagecount has been reduced to zero. In response to detecting that theoriginal overlay link usage count has shrunk to zero, the respectiveoriginal shared portion of the respective original file of the set oforiginal files may be removed. Removing may include deleting,eliminating, clearing, or otherwise erasing the respective originalshared portion of the set of original files. Aspects of the disclosurerelate to the recognition that, once all of the original overlay linkshave been switched to successor overlay links, system operations for theset of original nodes may have transitioned to the set of surrogatenodes and the respective original shared portion may no longer be needed(e.g., the surrogate nodes make use of the single successor sharedstorage segment for common data). Accordingly, the respective originalshared portion may be deleted, and storage space may be freed for use byother data or applications. Other methods of detecting that the originaloverlay link usage count has shrunk to zero and removing the respectiveoriginal shared portion are also possible.

In embodiments, an x86 processor may be absent with respect to theshared pool of configurable computing resources at module 554. x86processors may utilize software hypervisors for virtualization. x86processors can have additional layers with respect to non-x86processors. In certain embodiments, support for a hypervisor is builtinto the chip (e.g., embedded firmware managing the processor and memoryresources). Accordingly, the hypervisor may run as a piece of firmwarecode interacting with the hardware and virtual machines. In embodiments,the shared pool of configurable computing resources may make use of anadvanced interactive executive (AIX) or Linux based system architecture.Other types of system architectures are also possible.

In embodiments, the first respective successor individualized storagesegment may be modified without modifying the second respectivesuccessor individualized storage segment or the single successor sharedstorage segment at module 555. Generally, modifying can includeadjusting, editing, altering, revising, reading data, writing data, orotherwise changing the first respective successor individualized storagesegment. As described herein, aspects of the disclosure relate to a setof respective successor individualized storage segments for storing datathat applies or is particularly configured for a certain surrogate node.For instance, in embodiments, it may be desirable to make changes oradjustments to a particular surrogate node without affecting othersurrogate nodes of the set of surrogate nodes. Accordingly, aspects ofthe disclosure relate to modifying a first respective successorindividualized storage segment without modifying the second respectivesuccessor individualized storage segment or the single successor sharedstorage segment. In embodiments, modifying may include using the firstrespective overlay link to read or write data from the first respectivesuccessor individualized storage segment. As an example, modifying mayinclude installing a new service pack or technology level to aparticular surrogate node without changing the base OS image (e.g.,stored in the successor shared storage segment) or technologylevels/service packs (e.g., stored in other respective successorindividualized storage segments) of other surrogate nodes. Other methodsof modifying the first respective successor individualized storagesegment are also possible.

In embodiments, a distributed operating system update installation maybe carried-out and a plurality of logical partitions may be migrated atmodule 556. Generally, carrying-out can include completing,implementing, achieving, executing, or otherwise performing thedistributed operating system update installation. In embodiments,carrying-out may include performing the operating system updateinstallation on a set of cloud computing nodes located in differentgeographic locations (e.g., dynamically, simultaneously). Inembodiments, carrying-out may include installing/deploying the operatingsystem update on a physical memory space shared by a set of surrogatenodes (e.g., such that each surrogate node shares the same copy of theupdated operating system image). In embodiments, a plurality of logicalpartitions may be migrated within a threshold temporal period and usingless than a threshold amount of storage. Generally, migrating caninclude transferring, deploying, allocating, transmitting, sending, orotherwise moving a logical partition from one physical or virtuallocation to another. For instance, migrating can include relocating oneor more logical partitions from a first physical computing node to asecond physical computing node. In embodiments, migrating may includetransitioning system operations from a set of original nodes to a set ofsurrogate nodes. In embodiments, the plurality of logical partitions maybe migrated within a threshold temporal period (e.g., less than adefined time period; less than 30 minutes, less than an hour) and usingless than a threshold amount of storage (e.g., no more than a 10%increase to current storage usage; at least a 15% decrease in totalstorage usage compared to the current configuration). Other methods ofcarrying-out the distributed operating system installation and migratingthe plurality of logical portions are also possible.

FIG. 6 illustrates an example LPAR configuration 600 for operatingsystem update management, according to embodiments. Aspects of FIG. 6relate to a virtual input/output server (VIOS) 610 that iscommunicatively connected to a set of LPARs. In embodiments, the VIOS610 may include a set of files having a first file 612, a second file618, a third file 624, and a fourth file 630. Each file of the set offiles may correspond to a different LPAR of the set of LPARs. Forinstance, as shown in FIG. 6, the first file 612 may correspond to aLPAR 616, the second file 618 may corresponding to a LPAR 622, the thirdfile 624 may correspond to a LPAR 628, and the fourth file 630 maycorrespond to a LPAR 634. As described herein, each file of the set offiles may include a shared portion. As an example, the first file 612may include a shared portion 613. The shared portion may maintain a baseoperating system image that is common between the set of LPARs. As shownin FIG. 6, the set of LPARs may share a base operating system version of7.1.0.0. In embodiments, the shared portion of each file may map to asingle shared storage segment, such that each LPAR of the set of LPARsaccess a single base OS image. Accordingly, in embodiments, changes(e.g., updates) made to the single base OS image stored in the singleshared storage segment may be affect (e.g., be reflected) each LPAR ofthe set of LPARs.

In embodiments, as described herein, each file of the set of files mayinclude an individualized portion. As an example, the first file 612 mayinclude an individualized portion 614. The individualized portion maymaintain technology levels, service packs, or other files or data thatapply or are particularly configured for a certain LPAR. In embodiments,the individualized portion may include a first section and a secondsection. For instance, the individualized portion 614 may include afirst section 615 and a second section 617. In embodiments, the firstsection 615 may maintain technology levels or service packs that arespecific to a certain LPAR. In embodiments, the second section 617 maystore specific properties of a particular LPAR (e.g., characteristicsthat may remain unaffected by OS updates or other data/applicationinstallations). For instance, information such as IP addresses, physicalmemory addresses, and other such information may be maintained in thesecond section 617. In embodiments, changes or modifications made todata on the individualized portion of a file may remain specific to thatfile. Other methods of structuring LPAR configurations for operatingsystem upgrade management are also possible.

FIG. 7 illustrates an example node and physical memory spaceconfiguration 700 for operating system update management, according toembodiments. Aspects of FIG. 7 relate to using a set of original overlaylinks 702 to facilitate data communication between a first node file 710and a physical memory space 715. As described herein, aspects of thedisclosure relate to using a set of original overlay links to indicatethe saved location of data or information on the physical memory space715. For instance, the physical memory space 715 may maintain a set ofdata files (e.g., base operating system images) that may be accessed bylogical partitions (e.g., first node file 710) to facilitate systemoperations. As an example, the physical memory space 715 may include aset of data stored at a first memory address location 704 (e.g., memoryblocks 1000 and 2000). As described herein, aspects of the disclosurerelate to creating a set of overlay links 702 to map a portion of thefirst node file 710 to the memory address location 704. Accordingly, inembodiments, creating the set of overlay links 702 may includeregistering the memory address location (e.g., memory blocks 1000 and2000) of a particular data file to the first node file 710 such that thefirst node file 710 may access data saved at the memory address location704. Other methods of facilitating data communication between nodes andphysical memory spaces are also possible.

FIG. 8 illustrates an example node and physical memory spaceconfiguration 800 for operating system update management, according toembodiments. Aspects of FIG. 8 relate to using a set of successoroverlay links to facilitate data communication between a first node file810, a second node file 820, and a physical memory space 815. Asdescribed herein, aspects of the disclosure relate to establishing a setof successor files on a set of surrogate nodes, where each successorfile maps to single successor shared storage segment as well as one ormore respective successor individualized storage segments. Inembodiments, the first node file 810 may include a first successor fileon a first surrogate node, and the second node file 820 may include asecond successor file on a second surrogate node. In embodiments, thephysical memory space 815 may include a single successor shared storagesegment 816, a first respective successor individualized storage segment817, and a second respective successor individualized storage segment818. As described herein, the single successor shared storage segment816 may be used for store data or information that is common to multiplesurrogate nodes. For instance, in embodiments, the single successorshared storage segment 816 may maintain a single copy of a successorbase operating system image that may be used by at least the firstsurrogate node and the second surrogate node. In embodiments, the firstrespective successor individualized storage segment 817 and the secondrespective successor individualized storage segment 818 may maintaindata or information that is specific to a particular surrogate node. Forinstance, the first respective successor individualized storage segment817 may maintain a service pack specific to the first node file 810, andthe second respective successor individualized storage segment 818 mayinclude a technology level that is specific to the second node file 820.

As described herein, a set of successor overlay links may be used tofacilitate data communication between the physical memory space 815, thefirst node file 810, and the second file node 820. In embodiments, afirst subset of successor overlay links 802 may be used to indicate thesaved location of data or information on the physical memory space 815to the first node file 810. For instance, the first subset of successoroverlay links 802 may include a first successor overlay link 803 thatmaps to the single successor shared storage segment 816, and a secondsuccessor overlay link 804 that maps to the first respective successorindividualized storage segment 817. In embodiments, the memory address(e.g., memory blocks 1000 and 2000) of a shared data file (e.g.,successor base OS image) as well as the memory address (e.g., memoryblocks 4000 and 5000) of a data file specific to the node file 810(e.g., service pack) may be registered to the first node file 810. Inembodiments, a second subset of successor overlay links 805 may be usedto indicate the saved location of data or information on the physicalmemory space 815 to the second node file 820. For instance, the secondsubset of successor overlay links 805 may include a third successoroverlay link 806 that maps to the single successor shared storagesegment 816, and a fourth successor overlay link 807 that maps to thesecond respective successor individualized storage segment 818. Inembodiments, the memory address (e.g., memory blocks 1000 and 2000) of ashared data file (e.g., successor base OS image) as well as the memoryaddress (e.g., memory blocks 7000 and 8000) of a data file specific tothe node file 820 (e.g., technology level) may be registered to thesecond file node 820. In this way, both the first node file 810 and thesecond node file 820 may access and share common data files (e.g.,operating system images) from the single successor shared storagesegment 816 while maintaining individualized storage space (e.g., forservice packs and technology levels specific to certain surrogatenodes). Other methods of facilitating data communication between nodesand physical memory spaces are also possible.

In addition to embodiments described above, other embodiments havingfewer operational steps, more operational steps, or differentoperational steps are contemplated. Also, some embodiments may performsome or all of the above operational steps in a different order. Inembodiments, operational steps may be performed in response to otheroperational steps. The modules are listed and described illustrativelyaccording to an embodiment and are not meant to indicate necessity of aparticular module or exclusivity of other potential modules (orfunctions/purposes as applied to a specific module).

In the foregoing, reference is made to various embodiments. It should beunderstood, however, that this disclosure is not limited to thespecifically described embodiments. Instead, any combination of thedescribed features and elements, whether related to differentembodiments or not, is contemplated to implement and practice thisdisclosure. Many modifications and variations may be apparent to thoseof ordinary skill in the art without departing from the scope and spiritof the described embodiments. Furthermore, although embodiments of thisdisclosure may achieve advantages over other possible solutions or overthe prior art, whether or not a particular advantage is achieved by agiven embodiment is not limiting of this disclosure. Thus, the describedaspects, features, embodiments, and advantages are merely illustrativeand are not considered elements or limitations of the appended claimsexcept where explicitly recited in a claim(s).

The present invention may be a system, a method, and/or a computerprogram product. The computer program product may include a computerreadable storage medium (or media) having computer readable programinstructions thereon for causing a processor to carry out aspects of thepresent invention.

The computer readable storage medium can be a tangible device that canretain and store instructions for use by an instruction executiondevice. The computer readable storage medium may be, for example, but isnot limited to, an electronic storage device, a magnetic storage device,an optical storage device, an electromagnetic storage device, asemiconductor storage device, or any suitable combination of theforegoing. A non-exhaustive list of more specific examples of thecomputer readable storage medium includes the following: a portablecomputer diskette, a hard disk, a random access memory (RAM), aread-only memory (ROM), an erasable programmable read-only memory (EPROMor Flash memory), a static random access memory (SRAM), a portablecompact disc read-only memory (CD-ROM), a digital versatile disk (DVD),a memory stick, a floppy disk, a mechanically encoded device such aspunch-cards or raised structures in a groove having instructionsrecorded thereon, and any suitable combination of the foregoing. Acomputer readable storage medium, as used herein, is not to be construedas being transitory signals per se, such as radio waves or other freelypropagating electromagnetic waves, electromagnetic waves propagatingthrough a waveguide or other transmission media (e.g., light pulsespassing through a fiber-optic cable), or electrical signals transmittedthrough a wire.

Computer readable program instructions described herein can bedownloaded to respective computing/processing devices from a computerreadable storage medium or to an external computer or external storagedevice via a network, for example, the Internet, a local area network, awide area network and/or a wireless network. The network may comprisecopper transmission cables, optical transmission fibers, wirelesstransmission, routers, firewalls, switches, gateway computers and/oredge servers. A network adapter card or network interface in eachcomputing/processing device receives computer readable programinstructions from the network and forwards the computer readable programinstructions for storage in a computer readable storage medium withinthe respective computing/processing device.

Computer readable program instructions for carrying out operations ofthe present invention may be assembler instructions,instruction-set-architecture (ISA) instructions, machine instructions,machine dependent instructions, microcode, firmware instructions,state-setting data, or either source code or object code written in anycombination of one or more programming languages, including an objectoriented programming language such as Java, Smalltalk, C++ or the like,and conventional procedural programming languages, such as the “C”programming language or similar programming languages. The computerreadable program instructions may execute entirely on the user'scomputer, partly on the user's computer, as a stand-alone softwarepackage, partly on the user's computer and partly on a remote computeror entirely on the remote computer or server. In the latter scenario,the remote computer may be connected to the user's computer through anytype of network, including a local area network (LAN) or a wide areanetwork (WAN), or the connection may be made to an external computer(for example, through the Internet using an Internet Service Provider).In some embodiments, electronic circuitry including, for example,programmable logic circuitry, field-programmable gate arrays (FPGA), orprogrammable logic arrays (PLA) may execute the computer readableprogram instructions by utilizing state information of the computerreadable program instructions to personalize the electronic circuitry,in order to perform aspects of the present invention.

Aspects of the present invention are described herein with reference toflowchart illustrations and/or block diagrams of methods, apparatus(systems), and computer program products according to embodiments of theinvention. It will be understood that each block of the flowchartillustrations and/or block diagrams, and combinations of blocks in theflowchart illustrations and/or block diagrams, can be implemented bycomputer readable program instructions.

These computer readable program instructions may be provided to aprocessor of a general purpose computer, special purpose computer, orother programmable data processing apparatus to produce a machine, suchthat the instructions, which execute via the processor of the computeror other programmable data processing apparatus, create means forimplementing the functions/acts specified in the flowchart and/or blockdiagram block or blocks. These computer readable program instructionsmay also be stored in a computer readable storage medium that can directa computer, a programmable data processing apparatus, and/or otherdevices to function in a particular manner, such that the computerreadable storage medium having instructions stored therein comprises anarticle of manufacture including instructions which implement aspects ofthe function/act specified in the flowchart and/or block diagram blockor blocks.

The computer readable program instructions may also be loaded onto acomputer, other programmable data processing apparatus, or other deviceto cause a series of operational steps to be performed on the computer,other programmable apparatus or other device to produce a computerimplemented process, such that the instructions which execute on thecomputer, other programmable apparatus, or other device implement thefunctions/acts specified in the flowchart and/or block diagram block orblocks.

Embodiments according to this disclosure may be provided to end-usersthrough a cloud-computing infrastructure. Cloud computing generallyrefers to the provision of scalable computing resources as a serviceover a network. More formally, cloud computing may be defined as acomputing capability that provides an abstraction between the computingresource and its underlying technical architecture (e.g., servers,storage, networks), enabling convenient, on-demand network access to ashared pool of configurable computing resources that can be rapidlyprovisioned and released with minimal management effort or serviceprovider interaction. Thus, cloud computing allows a user to accessvirtual computing resources (e.g., storage, data, applications, and evencomplete virtualized computing systems) in “the cloud,” without regardfor the underlying physical systems (or locations of those systems) usedto provide the computing resources.

Typically, cloud-computing resources are provided to a user on apay-per-use basis, where users are charged only for the computingresources actually used (e.g., an amount of storage space used by a useror a number of virtualized systems instantiated by the user). A user canaccess any of the resources that reside in the cloud at any time, andfrom anywhere across the Internet. In context of the present disclosure,a user may access applications or related data available in the cloud.For example, the nodes used to create a stream computing application maybe virtual machines hosted by a cloud service provider. Doing so allowsa user to access this information from any computing system attached toa network connected to the cloud (e.g., the Internet).

Embodiments of the present disclosure may also be delivered as part of aservice engagement with a client corporation, nonprofit organization,government entity, internal organizational structure, or the like. Theseembodiments may include configuring a computer system to perform, anddeploying software, hardware, and web services that implement, some orall of the methods described herein. These embodiments may also includeanalyzing the client's operations, creating recommendations responsiveto the analysis, building systems that implement portions of therecommendations, integrating the systems into existing processes andinfrastructure, metering use of the systems, allocating expenses tousers of the systems, and billing for use of the systems.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

While the foregoing is directed to exemplary embodiments, other andfurther embodiments of the invention may be devised without departingfrom the basic scope thereof, and the scope thereof is determined by theclaims that follow. The descriptions of the various embodiments of thepresent disclosure have been presented for purposes of illustration, butare not intended to be exhaustive or limited to the embodimentsdisclosed. Many modifications and variations will be apparent to thoseof ordinary skill in the art without departing from the scope and spiritof the described embodiments. The terminology used herein was chosen toexplain the principles of the embodiments, the practical application ortechnical improvement over technologies found in the marketplace, or toenable others of ordinary skill in the art to understand the embodimentsdisclosed herein.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the variousembodiments. As used herein, the singular forms “a,” “an,” and “the” areintended to include the plural forms as well, unless the context clearlyindicates otherwise. “Set of,” “group of,” “bunch of,” etc. are intendedto include one or more. It will be further understood that the terms“includes” and/or “including,” when used in this specification, specifythe presence of the stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof. In the previous detaileddescription of exemplary embodiments of the various embodiments,reference was made to the accompanying drawings (where like numbersrepresent like elements), which form a part hereof, and in which isshown by way of illustration specific exemplary embodiments in which thevarious embodiments may be practiced. These embodiments were describedin sufficient detail to enable those skilled in the art to practice theembodiments, but other embodiments may be used and logical, mechanical,electrical, and other changes may be made without departing from thescope of the various embodiments. In the previous description, numerousspecific details were set forth to provide a thorough understanding thevarious embodiments. But, the various embodiments may be practicedwithout these specific details. In other instances, well-known circuits,structures, and techniques have not been shown in detail in order not toobscure embodiments.

1. A computer-implemented method of operating system update managementfor a shared pool of configurable computing resources having a pluralityof logical partitions (LPARs), the method comprising: receiving anoperating system update request for the shared pool of configurablecomputing resources; classifying, with respect to a set of originalfiles on a set of original nodes, a set of original shared portions anda set of original individualized portions, wherein a respective originalfile of the set of original files has a respective original sharedportion and a respective original individualized portion; creating, forthe set of original files on the set of original nodes, a set oforiginal overlay links including a respective original overlay link forthe respective original file of the set of original files; routing a setof operating system network traffic using the set of original overlaylinks; establishing, to succeed the set of original files on the set oforiginal nodes, a set of successor files on a set of surrogate nodes,wherein a first respective successor file of the set of successor filesmaps to a single successor shared storage segment and a first respectivesuccessor individualized storage segment, and wherein a secondrespective successor file of the set of successor files maps to thesingle successor shared storage segment and a second respectivesuccessor individualized storage segment; creating, for the set ofsuccessor files on the set of surrogate nodes, a set of successoroverlay links including: a successor shared overlay link which maps tothe single successor shared storage segment, a first respective overlaylink which maps to the first respective successor individualized storagesegment, and a second respective overlay link which maps to the secondrespective successor individualized storage segment; and routing, inplace of the set of original overlay links, the set of operating systemnetwork traffic using the set of successor overlay links.
 2. The methodof claim 1, further comprising: initiating, with respect to the set oforiginal files on the set of original nodes which have the set oforiginal overlay links, performance of a live kernel update (LKU)operation.
 3. The method of claim 2, wherein performance of the LKUoperation includes: invalidating the set of original overlay links;validating the set of successor overlay links; and freeing a chunk ofstorage corresponding to the set of original files.
 4. The method ofclaim 1, wherein the set of original shared portions includes a set oforiginal base operating system images.
 5. The method of claim 4, whereinthe set of original individualized portions is selected from the groupconsisting of: a set of original technology levels, and a set oforiginal service packs.
 6. The method of claim 1, wherein the singlesuccessor shared storage segment includes a single successor baseoperating system image which is common for the plurality of LPARs. 7.The method of claim 6, wherein the first respective successorindividualized storage segment includes a first successor technologylevel, and wherein the second respective successor individualizedstorage segment includes a second successor technology level whichdiffers from the first successor technology level.
 8. The method ofclaim 6, wherein the first respective successor individualized storagesegment includes a first successor service pack, and wherein the secondrespective successor individualized storage segment includes a secondsuccessor service pack which differs from the first successor servicepack.
 9. The method of claim 1, further comprising: carrying-out, whilemaintaining ongoing operating system availability, an operating systemupdate of the plurality of LPARs in both an automated fashion and adynamic fashion.
 10. The method of claim 1, further comprising:incrementing, for each original overlay link of the set of originaloverlay links, an original overlay link usage count.
 11. The method ofclaim 10, further comprising: decrementing, for each original overlaylink of the set of original overlay links switched to the set ofsuccessor overlay links, the original overlay link usage count.
 12. Themethod of claim 11, further comprising: detecting, in response to an LKUoperation, that the original overlay link usage count has shrunk tozero; and removing, in response to detecting that the original overlaylink usage count has shrunk to zero, the respective original sharedportion of the respective original file of the set of original files.13. The method of claim 1, wherein an x86 processor is absent withrespect to the shared pool of configurable computing resources.
 14. Themethod of claim 1, further comprising: modifying, without modifying thesecond respective successor individualized storage segment and withoutmodifying the single successor shared storage segment, the firstrespective successor individualized storage segment.
 15. The method ofclaim 1, further comprising: carrying-out a distributed operating systemupdate installation; and migrating the plurality of LPARs within athreshold temporal period using less than a threshold amount of storage.16. The method of claim 1, wherein the set of operational steps eachoccur in a dynamic fashion to streamline operating system updatemanagement.
 17. The method of claim 1, wherein the set of operationalsteps each occur in an automated fashion without user intervention. 18.A system of operating system update management for a shared pool ofconfigurable computing resources having a plurality of logicalpartitions (LPARs), the system comprising: a memory having a set ofcomputer readable computer instructions, and a processor for executingthe set of computer readable instructions, the set of computer readableinstructions including: receiving an operating system update request forthe shared pool of configurable computing resources; classifying, withrespect to a set of original files on a set of original nodes, a set oforiginal shared portions and a set of original individualized portions,wherein a respective original file of the set of original files has arespective original shared portion and a respective originalindividualized portion; creating, for the set of original files on theset of original nodes, a set of original overlay links including arespective original overlay link for the respective original file of theset of original files; routing a set of operating system network trafficusing the set of original overlay links; establishing, to succeed theset of original files on the set of original nodes, a set of successorfiles on a set of surrogate nodes, wherein a first respective successorfile of the set of successor files maps to a single successor sharedstorage segment and a first respective successor individualized storagesegment, and wherein a second respective successor file of the set ofsuccessor files maps to the single successor shared storage segment anda second respective successor individualized storage segment; creating,for the set of successor files on the set of surrogate nodes, a set ofsuccessor overlay links including: a successor shared overlay link whichmaps to the single successor shared storage segment, a first respectiveoverlay link which maps to the first respective successor individualizedstorage segment, and a second respective overlay link which maps to thesecond respective successor individualized storage segment; and routing,in place of the set of original overlay links, the set of operatingsystem network traffic using the set of successor overlay links.
 19. Acomputer program product of operating system update management for ashared pool of configurable computing resources having a plurality oflogical partitions (LPARs), the computer program product comprising acomputer readable storage medium having program instructions embodiedtherewith, wherein the computer readable storage medium is not atransitory signal per se, the program instructions executable by aprocessor to cause the processor to perform a method comprising:receiving an operating system update request for the shared pool ofconfigurable computing resources; classifying, with respect to a set oforiginal files on a set of original nodes, a set of original sharedportions and a set of original individualized portions, wherein arespective original file of the set of original files has a respectiveoriginal shared portion and a respective original individualizedportion; creating, for the set of original files on the set of originalnodes, a set of original overlay links including a respective originaloverlay link for the respective original file of the set of originalfiles; routing a set of operating system network traffic using the setof original overlay links; establishing, to succeed the set of originalfiles on the set of original nodes, a set of successor files on a set ofsurrogate nodes, wherein a first respective successor file of the set ofsuccessor files maps to a single successor shared storage segment and afirst respective successor individualized storage segment, and wherein asecond respective successor file of the set of successor files maps tothe single successor shared storage segment and a second respectivesuccessor individualized storage segment; creating, for the set ofsuccessor files on the set of surrogate nodes, a set of successoroverlay links including: a successor shared overlay link which maps tothe single successor shared storage segment, a first respective overlaylink which maps to the first respective successor individualized storagesegment, and a second respective overlay link which maps to the secondrespective successor individualized storage segment; and routing, inplace of the set of original overlay links, the set of operating systemnetwork traffic using the set of successor overlay links.
 20. Thecomputer program product of claim 19, wherein at least one of: theprogram instructions are stored in the computer readable storage mediumin a data processing system, and wherein the program instructions weredownloaded over a network from a remote data processing system; or theprogram instructions are stored in the computer readable storage mediumin a server data processing system, and wherein the program instructionsare downloaded over a network to the remote data processing system foruse in a second computer readable storage medium with the remote dataprocessing system.